1. Technical Field
This disclosure is directed to integrated circuits, and more particularly, to circuits for measuring voltage drops in integrated circuits.
2. Description of the Related Art
Modern integrated circuits (ICs) can have transistor counts that number in the hundreds of millions, and in some cases, over a billion. These transistors may be arranged to form logic circuits and, more generally, switching circuitry. While it is possible that multiple power domains may exist on a single IC, it is nevertheless possible that some power domains provide power to circuitry having a large number of transistors relative to the overall number implemented on the IC.
During operation of the IC, it is possible that a number of transistors may switch concurrently/simultaneously. In such instances, the amount of current demanded by the circuits can change significantly as a result of the switching. This can in turn lead to a temporary drop in the supply voltage (commonly referred to as voltage ‘droop’) for the particular power domain in which the transistors are implemented. To counter the effects of voltage droop, capacitors may be coupled between the supply voltage node and a reference node (e.g., ground). Nevertheless, significant voltage droops may still occur if enough circuits switch at the same time. However, due to the capacitance between the supply voltage node and the reference node, the voltage will eventually stabilize.